(a) Field of the Invention
The present invention relates to a method and apparatus for accessing a base station by service in a heterogeneous network environment.
(b) Description of the Related Art
While the standards for the previous communication systems have been individually developed, the concept of multi-RAT (Radio Access Technology), which is a combination of several standards such as LTE (Long Term Evolution), WiFi, etc., and the concept of multi-layers such as macrocell, femtocell, etc, which provides different coverage with a single standard, have emerged in recent years. Hence, the optimum integration and operation of these concepts are under active discussion from the systems point of view.
To optimally configure such a heterogeneous network and provide various services based on various QoSs (Qualities of Services), a block, such as a coordinator or JRRM (Joint Radio Resource Management), is placed at a base station's end or the network's end to integrate the heterogeneous network's radio resources acquired by multiple RATs and manage them in conjunction with each other; however, a user terminal has no functional block for such a function.
One of the important requirements for next-generation mobile communication systems is quality experienced by the user. Quality of experience differs from the conventional QoS, which is given as a system requirement, and involves subjective measurement from the user's perspective. It can be represented by QoE.
The conventional wireless communication systems did not take quality experienced by the user into account, and therefore user complaints about service rose and it was impossible to allocate the most appropriate radio resources reflecting the quality experienced by the user of various services.